Submission #823581

#	Time	Username	Problem	Language	Result	Execution time	Memory
823581		thimote75	Friend (IOI14_friend)	C++14	100 / 100	37 ms	9940 KiB

friend

#include "friend.h"

#include <bits/stdc++.h>

using namespace std;

using idata = vector<int>;
using igrid = vector<idata>;
using di    = pair<int, int>;

idata parents;
idata types;
idata A, B;
idata coeff;

igrid roads;

int createVersion (int parent) {
	parents.push_back(parent);
	types  .push_back(0);
	coeff  .push_back(0);
	A      .push_back(-1);
	B      .push_back(-1);

	return parents.size() - 1;
}

di compute(int node);

di computeI (int node) {
	int dp0 = 0;
	int dp1 = coeff[node];

	for (int next : roads[node]) {
		const auto data = compute(next);

		dp0 += max(data.first, data.second);
		dp1 += data.first;
	}

	return { dp0, dp1 };
}
di computeM (int node) {
	const auto AD = compute(A[node]);
	const auto BD = compute(B[node]);
	int dp0 = AD.first + BD.first;
	int dp1 = max(AD.first, AD.second) + max(BD.first, BD.second);

	for (int next : roads[node]) {
		const auto data = compute(next);

		dp0 += max(data.first, data.second);
		dp1 += data.first;
	}

	return { dp0, dp1 };
}
di computeW (int node) {
	const auto AD = compute(A[node]);
	const auto BD = compute(B[node]);
	int dp0 = AD.first + BD.first;
	int dp1 = max(BD.first + AD.second, AD.first + BD.second);

	for (int next : roads[node]) {
		const auto data = compute(next);

		dp0 += max(data.first, data.second);
		dp1 += data.first;
	}

	return { dp0, dp1 };
}
di compute (int node) {
	if (types[node] == 0) return computeI(node);
	if (types[node] == 1) return computeM(node);
	if (types[node] == 2) return computeW(node);
	return {0, 0};
}

// Find out best sample
int findSample(int n,int confidence[],int host[],int protocol[]){
	idata versions(n, -1);
	versions[0] = createVersion(-1);

	for (int i = 1; i < n; i ++) {
		int p = versions[host[i]];
		versions[i] = createVersion(p);

		int v = versions[i];
		if (protocol[i] != 0) {
			types[p] = protocol[i];
			versions[host[i]] = createVersion(p);

			int u = versions[host[i]];

			A[p] = u; B[p] = v;
			parents[u] = -1;
			parents[v] = -1;
		}
	}

	roads.resize(parents.size());
	for (int i = 0; i < parents.size(); i ++)
		if (parents[i] != -1)
			roads[parents[i]].push_back(i);
	for (int i = 0; i < n; i ++)
		coeff[versions[i]] = confidence[i];

	const auto data = compute(0);
	return max(data.first, data.second);
}

Compilation message (stderr)

friend.cpp: In function 'int findSample(int, int*, int*, int*)':
friend.cpp:103:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  103 |  for (int i = 0; i < parents.size(); i ++)
      |                  ~~^~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 8 / 8
• Subtask 3: 8 / 8
• Subtask 4: 19 / 19
• Subtask 5: 23 / 23
• Subtask 6: 31 / 31